Laserfiche WebLink
� AMBRIA <br /> The site is approximately 16,600 square feet, and is roughly square in shape. The site is <br /> identified by assessor's parcel number 261-140-07. Properties surrounding the subject property <br /> are a mixture of residential properties and commercial properties. Residential properties are <br /> located north and east of the subject site and commercial properties are located west and south of <br /> the subject site. <br /> FATE AND TRANSPORT MODELING AND REMAINING MASS <br /> The fate and transport model VLEACH(Version 2.2.0.2)was used to predict future groundwater <br /> impacts from MTBE-impacted soils previously detected beneath the subject site. Cambria used <br /> site specific data to calibrate the model. Site specific parameters that are most sensitive to the <br /> model output include MTBE concentrations, area,depth to groundwater,fraction organic carbon, <br /> soil texture, and soil-water content. The VLEACH model setup and results are presented in <br /> Appendix A,the soil analytical data are presented in Appendix B,and the groundwater analytical <br /> data are presented in Appendix C. A summary of the fate and transport modeling is presented <br /> below. <br /> The VLEACH model was run using maximum MTBE soil concentrations that were detected in <br /> soil samples collected from boring CPT-1 on July 15, 1998. CTT-1 was drilled near the <br /> southeastern product dispenser adjacent to soil samples X-1 and X-2 where up to 250 milligrams <br /> per kilogram (mg;1Kg) MTBE were reported at depths of approximately 15 and 18 feet below <br /> grade (fbg), respectively on April 24, 1996. The CPT-1 soil analytical data were used for <br /> modeling based on several reasons: <br /> • CPT-1 was drilled in the area where the highest MTBE concentrations were detected, - <br /> • the analytical data from CPT-1 provide an accurate vertical assessment of soil conditions <br /> in the source area from a depth of approximately 10 fbg to the groundwater surface, <br /> which was encountered at a depth of approximately 30 fbg. <br /> • CPT-1 soil analytical results demonstrate that MTBE concentrations initially detected in <br /> samples X-1 and X-2 at 15 and 18 fbg; respectively, were not confirmed as no MTBE <br /> was detected at 15 fbg in this boring,and - <br /> • the MTBE soil concentrations correlate well with the actual and modeled MTBE 7 <br /> groundwater concentrations detected in source area wells MW-1 and EW-1 prior to <br /> remediation. <br /> 0324 2 <br />